The present invention relates generally to a system and method for power management in monitoring and controlling a regenerative fuel cell and at least one powered device, and is specifically concerned with a system and method providing for the power management system to communicate with a user and at least one powered device over a communication interface.
The business world and our personal lives have become highly dependent on the communications industry. Technological advances have created the ability for individuals to access and control vast amounts of information from anywhere in the world using electronic devices such as computers and computer network systems. These electric consuming devices require a high level of reliable electricity along with minimal power interruptions. For example, in the industry of facilities automation management billions of dollars are spent each year on electricity delivered to homes, commercial facilities, industrial facilities, and on automated systems used for monitoring and controlling all aspects of these facilities. The automated systems can be highly sophisticated processing systems that require a steady, reliable supply of electricity.
The growth of technology has created one of the most important and fastest growing global problems because there is a growing gap between the reliability of the current electricity supply and the level of reliability actually needed by today""s electric consuming devices. The reliability of electricity supply in the United States is currently dropping because demand is increasing faster than supply. The growth of the electric supply has been curtailed, in part, because of the uncertainty due to the electric industry deregulation, increased environmental concerns, and opposition to new powerplants due to aesthetic reasons and the perceived health and safety risks.
Alternative methods of supplying reliable electricity are being evaluated such as distributed generation and energy storage. Distributed generation is the generation of electricity using many small generators scattered throughout a service territory. Distributed generation can be used to augment the local electricity supply without having to build additional large central-station powerplants.
Energy storage can significantly improve the electricity supply by storing energy at off-peak times for consumption during peak demand periods. This use of energy storage is often referred to as xe2x80x9cload levelingxe2x80x9d since it levels the power demand on the electric grid by the load. Load leveling is particularly useful when it is widely distributed and located at or near the point of electricity use, since it reduces the regional requirement for peak generating capacity and reduces the local requirements for transmission and distribution capacity. When energy storage is performed on the customer side of the electric meter, it is often called xe2x80x9cpeak shavingxe2x80x9d rather than load leveling. Many structures and facilities in remote locations or in developing nations use energy storage in the form of non-electric grid renewable energy systems such as a wind energy collector or solar power. These non-electric grid systems require backup generators or another means of energy storage to provide electricity when the wind is not blowing or the sun is not shining.
Many electric consuming devices require premium, highly reliable power well beyond typical 99.9% electric grid power supplied in the United States. The demand for premium power has traditionally been served with backup power systems or uninterruptible power systems (UPSs). All backup power systems and UPSs include some form of energy storage, generation, or combination of both. In current state-of-the-art systems, lead-acid batteries are generally used for energy storage and generators running on gasoline, diesel fuel, propane, or natural gas are used for generation. Lead-acid batteries are generally used because they provide instantaneous energy and can handle most power outages, which are generally under 20 minutes in duration. For power outages that are longer in duration, a generator can be configured to automatically supply electricity when needed.
There are several disadvantages in using lead-acid batteries for energy storage within a system including: (1) a limited energy storage capacity, (2) rapid deterioration when exposed to temperatures over 35xc2x0 C., (3) rapid deterioration if discharged without frequent recharges, (4) inability to provide continuous power backup since they take many hours to recharge, (5) contain a large amount of lead that is toxic, (6) the energy contained in the batteries cannot be physically extracted for use in other devices, and (8) impractical for daily load leveling or peak shaving due to limited cycle life.
Some of the disadvantages in using lead-acid batteries can be overcome by combining them with a generator, which introduces other disadvantages including (1) noise and emission of poisonous gases, (2) not electrically rechargeable and reliant on fuel that goes bad after prolonged storage, (3) operates using highly flammable fuels that create a hazard to personnel and property, and (4) requires a relatively high level of maintenance.
A fuel cell can overcome most of the problems encountered with using lead-acid batteries, a generator, or a combination of both. A fuel cell provides the ability to generate reliable electricity and to deliver that energy on demand to powered devices. Fuel cells come in many different forms including zinc fuel cells and various types of hydrogen fuel cells such as phosphoric acid, proton exchange membrane (solid polymer), molten carbonate, solid oxide, and alkaline. Fuel cells generally produce electricity by electrochemically reacting a fuel and a reactant resulting in a reaction product. The fuel cells provide a clean and efficient energy source by producing zero emission electricity.
A fuel cell that has the added ability to regenerate or reuse reaction product is even more environmentally friendly. These fuel cells are often called xe2x80x9cregenerative fuel cellsxe2x80x9d since the fuel cell includes hardware that can turn the reaction product back into fuel and reactant. This regenerative ability makes the regenerative fuel cell a perfect system to be used in remote locations, onboard a vehicle, and in facilities where it is inconvenient to periodically refuel the fuel cell.
Though still relatively undeveloped, regenerative fuel cells are now taking the form of hydrogen fuel cells and zinc fuel cells. A hydrogen regenerative fuel cell is configured for hydrogen and oxygen to be fed into the fuel cell. The resulting reaction results in the generation of electricity and a reaction product in the form of water. The water is recirculated back to a storage unit where it can later be regenerated back into hydrogen and oxygen. A zinc fuel cell is configured for zinc and oxygen to be fed into a fuel cell along with an electrolyte. The electrolyte is used as the transport medium for the zinc fuel, which is usually in the form of small particles. The resulting reaction results in the generation of electricity.and a reaction product in the form of zinc oxide. The zinc oxide is recirculated back to a storage unit where it can later be regenerated back into zinc and oxygen.
The lack of significant energy storage capacity in the electric distribution system, combined with shrinking excess generating capacity, has caused and will continue to cause a reduction in the reliability of the electricity supply in the United States and developing nations, which have an even less reliable electric supply.
As the global community becomes more dependent on highly specialized electronic devices, the need for reliable electricity will increase along with the need to manage the supplied electricity. Power management in monitoring and controlling the electricity to these powered devices is essential in assuring that with increasing power loads the powered devices will have reliable power along with power backup when needed. Communication between the electric grid, the fuel cell, and powered devices is necessary to monitor and control operating conditions for reliable power.
As air pollution and rising fuel costs become increasingly important for operators of long-haul trucks and other vehicles, it is becoming more important for the operators of these vehicles to adopt new zero-emission technologies for powering auxiliary devices. For example, it is estimated by the US Department of Energy that the average long-haul heavy-duty truck spends up to $4,500 per year in fuel, repairs, and shortened engine life due to idling the truck""s main engine to power auxiliary devices such as the television and air conditioner when the truck is parked. An on-board power management system incorporating a regenerative fuel cell could solve this problem.
For the reasons described above, there remains a need for a power management system that provides for monitoring and controlling a regenerative fuel cell and at least one powered device using energy storage for backup power, UPS, or load leveling/peak shaving applications, is electrically rechargeable or rapidly refuelable, and incorporates a method for communicating over an interface with a user, a regenerative fuel cell, and at least one powered device for sending and receiving data.
It is an object of the present invention to provide a power management system for supplying reliable electricity to be used for backup power, load leveling/peak shaving, supplying a regional electric grid, or powering electric consuming devices in a manner that is environmentally safe.
It is a further object of the present invention to provide a power management system with a regenerative fuel cell that is electrically rechargeable or rapidly refuelable by having a refillable fuel system utilizing refillable transportable containers.
It is still another object of the present invention to provide a power management system that monitors and controls a regenerative fuel cell and at least one powered device.
It is an object of the present invention to provide a power management system that provides for communication between a user, a regenerative fuel cell, and at least one powered device over a communication interface.
It is a further object of the present invention to provide a power management system that provides generated electricity to powered devices located onboard a vehicle and where the electricity is used to propel the vehicle or to power auxiliary devices onboard the vehicle.
It is still another object of the present invention to provide a power management system that is compact, efficient, and easy to use.
Additional objects include any of the foregoing objects, singly or in combination.
According to one aspect of the present invention, the power management system comprises a regenerative fuel cell and a communication interface configured to allow communication of data between the regenerative fuel cell and an external device, wherein the regenerative fuel cell is configured to deliver and receive power responsive to one or more parameters received from the external device over the interface.
The regenerative fuel cell comprises a fuel storage for storing fuel, a fuel cell for electrochemically reacting the fuel with a second reactant to release electricity, a reaction product storage for storing reaction product resulting from the reaction, a fuel regenerator for electrochemically recovering the fuel from the reaction product, and an optional second reactant storage unit. In some cases, the fuel cell itself may be used to regenerate the fuel. A communication device may be provided for monitoring and controlling the regenerative fuel cell, at least one powered device, and at least one energy source.
The power management system may further include a power interface, wherein electricity can be sent and received over the power interface; at least one energy source in communication with the communication device, the at least one energy source providing electricity to the regenerative fuel cell and at least one powered device, wherein the regenerative fuel cell can send electricity to and receive electricity from the at least one energy source. The system may further include a user interface for exchanging data between a user and the regenerative fuel cell or device.
In another aspect of the present invention, a method for remotely controlling a regenerative fuel cell comprises the steps of inputting data over a user interface; providing the data to the regenerative fuel cell over a communication interface; and configuring the regenerative fuel cell to deliver power responsive to the data. The data comprises control parameters for the regenerative fuel cell.
In another aspect of the present invention, a method for monitoring at least one powered device comprises the steps of gathering data from at least one powered device; transmitting the data from at least one powered device to a regenerative fuel cell over a communication interface; and receiving and storing the data on a communication device in communication with the regenerative fuel cell. The data can be transmitted to a user. The data can be selected from the group comprising power usage information, environmental information, operating parameters, and control parameters.
The method for monitoring at least one powered device may further comprise the steps of comparing the data against preset control parameters supplied by a user; delivering power to the powered device responsive to the data; receiving the updated control parameters by at least one powered device; sending the updated control parameters from the powered device to other powered devices; and adjusting operation to perform within the updated control parameters.
In another aspect of the present invention, a method of power management for monitoring and controlling a regenerative fuel cell and at least one powered device through the use of a communication device comprises the steps of receiving power delivery requests; activating the regenerative fuel cell by commands from the communication device; electrochemically reacting a fuel and a second reactant; generating electricity and a reaction product from the reaction; and delivering the generated electricity.